Process and apparatus for making bags from nonfibrous sheet material



Oct. 2, 1951 G; w. FRENCH v PROCESS AND APPARATUS FOR MAKING BAGS FROM NONFIBROUS SHEET MATERIAL Filed Nov. 30, 1948 2 Sheets-Sheet l Inventor.- c-w'ao/v HI IA FEE/V05 per AZ Hwy.

Oct. 2, 1951 G. w. FRENCH PROCESS AND APPARATUS FOR MAKING BAGS FROM NONFIBROUS SHEET MATERIAL 2 Shee'w-Sheet 2 lnvenlbn 50 700 w/a 0m. F/ffWC/i aer' Filed Nov. 30, l948 Ab orney 4 Patented Oct. 2, 1951 PROCESS AND APPARATUS FOR MAKING BAGS FROM NONFIBROUS SHEET MATE- RIAL Gordon William French, Bedminster, England,

assignor to Beasley, French & Company Limited, Bedminster, England, a British company Application November 30, 1948, Serial No. 62,630 In Great Britain December 3, 1947 2 Claims. 1

This invention relates to the manufacture of bags, envelopes and the like made from transparent or translucent viscose, regenerated cellulose or like sheet materials. Considerable difficulty is'encountered'in the'manufacture of bags, envelopes and the like from such material by the methods at present employed owing to the liability of such sheet materials to develop irregular splits or cracks and especially in the angles or folds between two out edges.

In the usual method of manufacture of bags, envelopes or the like, a web of sheet material is folded into a flattened tubular form and fed along a former plate and severed into suitable sections of the desired length by means of a beaterbar and breaker plate or by upper and lower cutters which act to effect a stepped severance of the upper and lower layers of the flattened tube to provide a flap or flaps for folding over to effect a closure of one or both ends of the bag, envelope or the like. The chief object of this invention is to provide an improved apparatus whereby the severance of the flattened tube into suitable short lengths is effected in a clean and unbroken manner. A further object is to enable bags, envelopes and the like to be produced at a high rate.

According to this invention, the flattened tube has cut out at the opposite edges short segments of the sheet material at intervals corresponding to the position at which the tube is to be severed into bag lengths. These cuts separate the two layers of the tube and provide slots into which the severing cuts extend. For this purpose as stated the folded edges of the material are cut away at the position where the severing cuts occur and the cut away portions preferably extend for a distance equal to or Slightly greater than the distance between the stepped cuts in the two layers of the flattened tube of material. In the case of bags of the satchel type in which the folded tube of sheet material is formed with a double fold or pleat at both sides, the cut away portions may be removed from the folded edges of one layer only, but if desired additional small perforations only may be made in the edges of the other layer.

In order that the invention may be understood there is appended thereto two sheets of drawings illustrating diagrammatically one way of carrying the invention into practice.

In the drawings:

Fig. 1 is a side elevation,

Fig. 2 a plan.

Fig. 3 a view of the web of material showing a severed bag length,

Fig. 4 an end view of the cutter forming the recess, and

Fig. 5 a side View thereof.

In the example illustrated of how the invention may be carried into practice, a web of suitable transparent or translucent viscose sheet material is folded into a flattened tubular form I and la and is fed between suitable draw rolls 2, 2 over a suitably shaped former plate 3 in the usual well known manner. The flattened tube of sheet material is fed along the former plate to suitable holding rolls 4, 4 placed above and below the former plate and which may operate through apertures 5 therein. Suitable upper and. lower stabilising rolls 8, 6 are placed above and below the former plate near its free end and the end of the plate may be thickened and suitably bevelled. As the plate increases in thickness toward its free end'it is correspondingly decreased in width to maintain a substantially uniform peripheral dimension round a transverse section of the plate at all positions.

At suitable positions between the draw rolls 2, 2 and the holding rolls 4, 4 suitable rotary or other cutters l are provided to remove the required section from the folded edge of the flattened tube at both sides thereof. The sections or segments 8 removed from the edge of the tube at both sides thereof, are of elongated form with rounded ends. The cuts may be effected by means of top and bottom rolls 1 and 1a operating in recesses IS in the edge of the former plate. As an alternative arrangement rotary cutters acting against the thickened edge of the former plate could be arranged to form elongated slotted openings in both sides of the flattened tube of material at the required intervals and of the desired shape and size.

Close to the free end of the former plate are mounted upper and lower cutter blades 9, l0 adapted to effect the stepped severance of the upper and lower layers of the flattened tube of material. These cutter blades are mounted and actuated so as to periodically intersect the path of travel of the material and to move with and at approximately the same speed as the material. For this purpose the cutter blades may be mounted to rotate so that the cutting edges move in circular paths which intersect the separated upper and lower layers of sheet material and travel at approximately the same speed and in the same direction as the sheet material. In one arrangement the cutter blades could be actuated through parallel link mechanism.

Actual severance of the section of flattened tube of sheet material is effected by a sharp pull on the section to be severed. This may be effected by gripping or snatch rolls II, II rotating at a greater peripheral" speed than the flattened tube of sheet material and which periodically grip and impart a sharp pull upon the end section of the flattened, tube when the cutter blades are correctly positioned sothat; each layer of sheet material will be sharply tensioned against the deflecting, edge of the. respective cutter blades. Either one or both gripping rolls may be provided with suitably positioned segmental protuberances l2 for this purpose.

The cutter blades may comprise-fiat or shaped steel blades having sharpened cutting edges andthese cutting edges are preferably serrated. as shown at l3 to provide sharp pointed teeth having bevelled or faceted cutting edges. The. cuttin edges of the blades may be inclined and so actuated as to effect the cut progressively across the width of the sheet material from side to side from the centre outwards or from the edges inwardly. Even though the cutting edges may be serrated they are so directed as to effect a clean smooth out which, may be an unbroken straight line,, or if it be curved or otherwise deviates from a straight line, sharp angles should be avoided in the cut, edge of the material. as these tend to start splits or tears therein.

The various movable parts are driven in any convenient way. The drive may be from a main drive with suitable gearing such as indicated by I! interposed between this and the various parts to give the, desired speeds to the latter.

Pressure regulating means and adjusting means may be used with the various pairs of rolls and severing, and edge cutters- In Fig. 3' there is shown a severed bag length, I8, 14' indicating the top, out and 15 the bottom cut.

I claim:

1. In a process for producing bags from a length of non-fibrous sheet material, the steps comprising folding the longitudinal edges of the length into overlapping relation to form a tube, flattening the tube, cutting out of the opposite edges of" said tube a short segment of the sheet material at spaced points along said length, the ends of the cut out segment being curved, and thereafter severing the tube transversely along a line passing between the inner ends of said out.

2. In an apparatus for producing bags from a flattened tubular length of non-fibrous sheet material, the combination of, a fixed former, having apertures therein, over which the sheet material is passed in the formof a tube, tube-holding rolls Operating through said apertures to grip said tube, slot-cutting means rotatably mounted in a vertical plane about a horizontal axis for cutting out short. segments to form slots at spaced points in opposite edges of the flattened tube, the ends of the slots being curved, and means to sever the flattened tube transversely after the slots, have been cut therein and intermediate the ends ofv two opposing slots, and snatch rolls for periodically gripping and imparting a pull upon the section of the tube to be severed, said slot-cutting means being positioned to operate on said tube while it is on said former and prior to its passing; to said transverse severing means.

GORDON WILLIAM FRENCH.

REFERENCES CITED The following references are of record in the filev of this patent:

UNITED STATES PATENTS Number Name Date- 1,851,960 Poppe Mar. 29, 1932 1,941,272 Potdevin Dec. 26, 1933 23911795 Potdevin et al Aug. 31, 1937 2,997,183 French Oct. 26, 1937 2,256,506 Wagner Sept. 23, 19,41 

